1. Field of the Invention
This invention is directed to an improved system for providing working access to a sealed enclosure such as a glove box. Glove boxes are generally leak-proof rigid-walled chambers, generally transparent so as to permit the interior to be viewed from the outside, and provided with a plurality of ports in each of which a glove is secured such that a technician may insert his hands through the ports into the gloves and perform manipulative operations within the enclosed chamber. The interior of the chamber is sealed off from the surrounding environment either to protect the operator and the outside environment from contamination by hazardous materials within the chamber, or to protect materials within the chamber from contamination by exposure to atmospheric air.
This type of chamber may be used for the handling of various noxious or hazardous materials, radioactive objects, and the like. Leak-tightness is essential. While this may be achieved relatively easily in a one-time installation, it is extremely difficult to replace parts such as to replace a glove, without loss of integrity of the seal of the chamber environment. In existing glove boxes the range of maneuverability of the operator is limited by the size and shape of the port opening through which the hand and arm extend and by the length of the glove. Gloves with long heavy sleeve portions tend to be difficult to extend and retract. Wear and damage most frequently occur to the hand enclosing portion of the glove but it is necessary that the entire glove, which is relatively expensive, be replaced.
2. The Prior Art
Applicant's prior U.S. Pat. No. 4,010,588 discloses a system by means of which one glove in sealing engagement with a port in a glove box can be replaced with another while preserving the integrity of the seal separating the environments on the opposite sides of the chamber wall while the exchange is taking place. This system performs admirably for its intended purpose but is limited to the replacement of an entire glove with long integral sleeve portion which is sealed in the port into the chamber.
Grieb U.S. Pat. No. 2,600,240, and Gibbon U.S. Pat. No. 2,598,532 both show infant incubators with ports in which long lightweight flexible plastic sleeves may be sealed. The sleeves are shown formed with corrugations or convolutions. However, because absolute integrity of the interior environment is not essential, the sleeves do not carry gloves but merely are provided with open elastic cuffs through which the hand is extended with the elastic cuff engaging the wrist in partial sealing engagement.